The test comprises of
~ 65 multiple choice questions
2-4 short answer … less than 1 page each with diagrams)
KNOW YOUR UNITS
kg mass
meter (m), km, ft, mile, inch distance
meter/second (m/s), mph, km/hr speed / velocity
meter/second
2
(m/s
2
, m/s/s)
acceleration
Newton (N) = kg*m/s
2 force
Basic scientific notation ( if something is correctly written )
Basic significant figures ( how many a number has )
Kinematics
Distance is total length traveled
Displacement is difference form beginning to end point o With no acceleration:
x = v*t o With acceleration:
x = v*t + 1/2 a*t
2 o Need to know relation, not really the math.
Velocity (speed) = change in displacement / change in time o V average
=
x / t o Know relation and maybe simple problem with equation
Acceleration = change in velocity / change in time o A average
=
v / t o Know relation and maybe simple problem with equation
Graphical Analysis of Motion
KNOW what graphs of different types of motion look like
(both d vs. t and v vs. t graphs) {mini-graphs} o Zero velocity o Constant velocity o Accelerated motion
Slope of “position – time graph” is velocity
Slope of “velocity – time graph” is acceleration
Area under “velocity – time” graph is displacement
Vectors
Have magnitude (size) and direction
Are added by placing them head to tail
Can be thought of in components
Basic Sine, cosine, tangent SOH-CAH-TOA
Basic adding of them in 1 dimension o i.e., 40 right and 10 left equals 30 right. o 10 N up and 3 N down equals 7 N up.
Projectile Motion
A projectile is an object where the only force acting is gravity
All objects fall with same acceleration that never changes o On Earth g = 9.8 m/s
2
, on Moon it is about 1.6 m/s
2
A projectile’s horizontal velocity is constant
A projectile’s vertical velocity continuously increases in the negative direction. o Slows down when going up o Speeds up when going down
At top of projectile path, V yo
= 0
X-displacement [
x= velocity * time] so each second object travels the same distance horizontally
Y-displacement [
y = V yo
*t – ½*g*t
2
], so each second object falls a greater distance than the previous second.
45° shot angle gives maximum range (X)
Forces
Newton’s Laws o 1: Law of Inertia:
(increase) mass means
(increase) inertia
object in motion wants to stay in motion, object at rest wants to stay at rest. o 2: F=m*a to have acceleration there must be a net force, and if there is a net force, there will be acceleration
F
a;
m
a o 3: Action – Reaction: forces always act in equal magnitude/opposite direction pairs
Net Force = mass*acceleration **
F = m*a o constant velocity or at rest = NO net force o changing velocity = YES net force
Net force = sum of forces taking into account direction o 10 N left and 30 N right; F net
= 30-10 = 20N o 20 N up and 10 N up; F net
= 20 + 10 = 30 N
Weight = mass * acceleration of gravity ** F g
= m*g
F f
=
*F
N
Momentum (pre read in book Chapter 7 pp. 86-98)
Momentum = mass * velocity
Impulse = Force * time o Increase impact time decreases impact force
Impulse-Momentum Theorem
Impulse = change in momentum, J =
p
In a collision, momentum is conserved